DESCRIPTION, OVERALL (provided by applicant): This application represents the third competing renewal of the Boston Obesity Nutrition Research Center. The Boston Obesity Nutrition Research Center represents a collaboration of three major universities representing six major organizations, all located within a 1.5 mile radius of one another. The Boston Obesity Center includes Tufts-New England Medical Center, Beth Israel Deaconess Medical Center, Massachusetts General Hospital, Harvard School of Public Health, Boston Medical Center and the Human Nutrition Research Center on Aging. These institutions represent Tufts University, Harvard University and Boston University, respectively The research base has increased from 97 to 163 and includes members from these institutions as well as several new ones, including the University of Massachusetts Boston and the University of Massachusetts Medical School (Worcester) and it affiliated University Center for Excellence in Developmental Disabilities at the Eunice Kennedy Shriver Center in Waltham. The Boston Obesity Nutrition Research Center consists of four Core laboratories. These include an Adipocyte Core directed by Dr. James Kirkland, a Clinical and Community Research Core directed by Dr. Aviva Must, an Epidemiology and Genetics Core directed by Dr. Frank Hu and a Transgenic Core directed by Dr. Bradford Lowell. The Obesity Center offers many opportunities for education and training in obesity research to fellows on training grants held by Obesity Center investigators in each of the collaborating institutions. The investigators represented in this application are Principal Investigators on 171 funded NIH grants, approximately 143 of which are directed at the study of obesity, energy metabolism or other nutritional diseases. In the past five years, the Boston Obesity Center investigators have published 283 papers with Center support. Currently, fifteen percent of the Obesity Center's budget provides support for pilot and feasibility studies. Pilot and feasibility award recipients have published 640 papers and received a total of 41 grants from NIH or other funding agencies based on the data obtained from their Center-funded and subsequent research in obesity and nutrition.